The ability to quickly and accurately navigate through and traverse over lightly to moderately wooded and/or thicketed terrain, along particular points of a specific line of travel, without the assistance of conventional land-based survey techniques and crew, and in the absence of permanently damaging the land, is of significant importance. Presently it is a difficult task to clear small to moderate sized brush consisting of small trees having diameters of up to 5 inches, thick briar patches, overgrown vines, grasses and weeds, all in an effort to accurately locate and travel a desired line of travel and a plurality of specific points along that line. Often, the desired path or line of travel may, for example, include property lines, seismic lines, rights-of-way and the like. Even where the survey coordinates, longitude and latitude coordinates or other types of location data are known for the specific property line, seismic line or right-of-way, brush and overgrown vegetation present significant barriers to physically locating these pathways. Various types of soil damaging equipment such as bulldozers, road scrapers and other types of heavy equipment may be used to knock down and push aside brush, however the soil damage incurred to the land generally outweighs the benefit of using this type of equipment. In the past, the location and clearing of property lines, seismic lines, rights-of-way and the like, in lightly to moderately wooded and/or thicketed areas has generally required a surveyor and a lead survey crew to begin at a known location and slowly and methodically hand cut its path and measure the appropriate distance in the desired direction to locate property lines, seismic lines, rights-of-way and the like, while a brush clearing crew and/or a brush clearing device follow behind the surveyor. Although this procedure for identifying property lines, seismic lines, rights-of-way and the like is generally accurate, it is nonetheless, very slow, labor intensive and expensive.
It would be of great benefit to not only be able to quickly and accurately navigate through and traverse over lightly to moderately wooded and thicketed terrain, but, at the same time to be able to locate a desired direction of travel and a plurality of specific points along the line of travel, and clear a pathway through the wooded and thicketed areas to provide easy access for motorized and/or foot traffic through said pathway.
Heretofore, there have been no methods of navigating which integrate an apparatus locator system, an apparatus guidance system, and a navigation system, with a brush cutting, chipping and clearing apparatus, which provides for navigating a remotely guided brush cutting, chipping and clearing apparatus over property lines, seismic lines, rights-of-way and the like, while clearing a pathway for motorized and/or foot traffic, without the need for traditional survey procedures. For the apparatus locator system to be effective throughout the world, it would need to be dependent on a satellite guidance system. One apparatus locator system may include, for example, communications equipment which could receive signals from the Global Positioning System (GPS) satellite network. A detailed explanation of the Global Positioning System is set forth in U.S. Pat. No. 5,155,490, GEODETIC SURVEYING SYSTEM USING MULTIPLE GPS BASE STATIONS, issued to Spradley, Jr. et al. The GPS satellite network comprises 24 satellites which produce positioning signals and provide for the calculation of distance measurements. A minimum of three GPS satellite signals are necessary to determine any position on the earth. The GPS satellite signals can be received by one or more base stations, located at various positions on the earth's surface, and by a GPS antenna which may be mounted to the apparatus. The base station may receive and interpret the GPS satellite signals, however the base station produces a differential correction signal for use with the GPS satellite signals. The base station in turn sends the differential correction signal to a communication satellite which conveys the differential correction signal to a radio antenna mounted to the apparatus, or alternatively, the radio antenna may receive the differential correction signal directly from the base station. Additionally, a dual purpose antenna can receive both the GPS satellite signals and the differential correction signal from the base station. The differential correction signal and the GPS satellite signals can be simultaneously interpreted by the guidance system, wherein the differential correction is applied to calculate the current position of the vehicle from the GPS satellite signals. The corrected position and location of the apparatus, with respect to the earth and the desired direction of travel, can then both be displayed by the guidance system, in selectively either a graphic manner or a digital manner. An operator, stationed on board the apparatus or remotely stationed from the apparatus but having access to the guidance system, could view the guidance system and in response thereto maneuver the apparatus to cut, chip and clear small to moderately sized brush while traveling in a desired direction, i.e. over property lines, seismic lines, rights-of-way and the like. The GPS satellite signals provide very accurate guidance information where they can be received and where the positioning signal can be conveyed to the receiver antenna. However, in thickly forested areas or other areas having dense overhead or "canopy" cover, the GPS satellite signals may not always be effectively received. Thus the need arises for alternate apparatus locator systems which can be used in areas having canopy cover. An alternate apparatus locator system which may be used in areas having canopy cover may include, for example, an automated or semi-automated geodetic survey system, independent of guidance satellite signals. One such semi-automated geodetic survey system, may, for instance comprise the Geodimeter.RTM. System 4000. The Geodimeter.RTM. System 4000 is an automated survey system consisting of a transportable station unit positioned at a known point and a mobile reflector, generally mounted to a transportable carrier or vehicle. The station unit continuously conveys laser signals to the reflector, as the reflector moves away from the station unit. The laser signals are then reflected back to the station unit and measurement data is collected by a guidance system which may for example be a control unit or data processor which may be affixed adjacent to the reflector. The laser signals are processed at the station unit and a radio signal is sent to the guidance system. The radio signal is processed by and displayed by the guidance system, thus informing the operator as to the present location of the apparatus and the desired direction of travel.
Therefore, a need exists for a method of navigating a remotely guided brush cutting, chipping and clearing apparatus having a locator system for determining the location of the apparatus and a guidance system for determining the desired direction of travel for the apparatus and for navigating along specific points of a particular line of travel, relative to the surface of the earth. Additionally, a need exists for a method of logging or recording the points traversed by the apparatus, of the line of travel, relative to the surface of the earth.
Although the need for such a device and method of navigating has been long felt, the prior art, heretofore, has not provided such a device or method which meet all of the aforementioned criterion.
Additional features and advantages of the invention will be set forth in part in the description which follows, and in part will become apparent from the description, or may be learned by practice of the invention. The features and advantages of the invention may be realized by means of the combinations and steps particularly pointed out in the appended claims.